Vehicle door panel manufacturing method

ABSTRACT

The present invention provides, in a preferred embodiment, an interior trim component for a motor vehicle including a first membrane with a connected foam backing, an apertured second membrane spread adjacent the foam backing of the first membrane, and a moldable rigid polymeric material providing a backing for the second membrane and supporting the first membrane, the moldable polymeric material penetrating the apertures of the second membrane and adhering to the foam backing of the first membrane.

This is a division of application Ser. No. 08/041,109 filed on Apr. 1 ,1993, now U.S. Pat. No. 5,403,645.

FIELD OF THE INVENTION

The field of the present invention is that of methods of manufacture ofinterior trim components, especially door panels, for automotivevehicles.

BACKGROUND OF THE INVENTION

Many automotive interior door panels are molded to have a two-tonetexture color appearance. Typically, there is a main surface whichcovers the entire panel which is covered with a first color of vinyl.Located within the interior of the panel is an insert which is coveredwith an alternative color of vinyl or cloth. The insert typically alsohas additional foam padding to make it softer than the remainder of thepanel, which is rigid. Typically, the insert is attached to the firstcolor vinyl-covered rigid backing by gluing or some type of fastenerarrangement.

SUMMARY OF THE INVENTION

The present invention provides an alternative interior trim componentespecially useful in vehicle doors which provides a two-tone effectwhich minimizes or totally eliminates any requirement for gluing or theutilization of fasteners to attach the insert to the vinyl-covered rigidbacking, thereby reducing time and manufacturing and associated costs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a perspective view of an interior door panel utilizing apreferred embodiment of the present invention.

FIG. 2 is a view taken along line 2--2 of FIG. 1.

FIGS. 3 and 4 are a cross-section of the interior door panel as shown inFIG. 2 during the manufacturing process, positioned within a mold.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates an interior door panel 7 of the present invention.The interior door panel 7 has a base flexible vinyl skin 10 covering aglass-reinforced urethane rigid backing 20. A cloth skin can besubstituted for the flexible vinyl skin so long as it has a nonporousbacking. An insert 30 is provided in the door panel 7 which, in theexample shown, has a membrane cover of cloth 12, although vinyl could beutilized. The cloth insert has an additional soft foam backing 14 oftenutilized to provide padding to the interior door panel 7 or for comfortor a decorative appearance.

Referring to FIG. 2, the insert is formed in a separate operation. Asmentioned previously, the insert has a vinyl or cloth membrane skin 12.Connected with this flexible membrane skin 12 is a soft foam backing 14,an example of which is polyether open or closed cell. The foam backing14 has joined (by gluing) to its side opposite the cloth skin 12 aplastic film, such as sold under the trademark "MYLAR", backing 16 forreasons to be later described. The plastic film backing 16 is capturedbetween the foam backing 14 and the vinyl skin 10.

Referring additionally to FIGS. 3 and 4, in the manufacturing processthe insert 30 is lowered into the lower half 18 of the mold 22. The mold22 has an integral blade 24 typically matching the shape of the insert,and the insert is compliantly held in position by insertion within theblade 24. The blade 24 is typically fabricated from a durablenoncorrosive material such as stainless steel. To aid in retaining theinsert 30 in its proper location during the molding process, the insert30 is exposed to a series of vacuums which are provided in apertures 26of the mold lower half. In some embodiments of the present inventiveprocess, the blades 24 may be entirely eliminated and the vacuum will berelied upon for positional fixation of the insert 30 within the moldcavity.

Stretched over the top of the blades is the backing cover or secondmembrane 10 typically comprised of vinyl material such as a solidlayer-blowing agent bilaminate flexible PVC acrylonitrile butadienestyrene copolymer or other suitable alternatives. The membrane 10 isheld in position by a series of dowel pins 28 in tension to insure alack of wrinkles in the finished part. This membrane has a series ofaperture perforations 32 which typically measure 0.125 inches indiameter and are scattered on two-inch centers. The membrane 10 capturesthe foam backing 14 between itself and the membrane skin 12.

On top of the vinyl membrane 10 is placed a glass fiber reinforcementmat. The mat is a random weave one ounce per square foot material. Ifdesired, the glass reinforcement mat can be deleted and the glass fiberscan be mixed with the urethane.

The upper half 34 of the mold is closed. The mold is aluminum and hasalready been preheated to a temperature of 135° F. to 150° F. Theurethane (a two-part isocyanate-polyol mixture) is injected on the sideof the membrane 10 opposite the insert 30 at a rate of approximately 250grams per second and at a temperature of approximately 85° F., fillingthe space behind the membrane 10 and thereafter seeping through thevarious apertures 32 in the membrane, adhering to the plastic filmbacking material 16, which provides a third membrane or backing for theinsert 30. The plastic film backing 16 prevents penetration of theglass-reinforced urethane 20 into the soft foam backing 14 of the insert30 to prevent the insert from having various hard spots.

The urethane can be Imperial Chemical Industries 8700A/8711B with amixing ratio of 0.535 grams of isocyanate (8700A) to one gram of polyol(8711B). The cream time is six seconds, and the gel time is 23 seconds.The end of reaction (EOR) time is 33 seconds, and the free rise density(FRD) is 4.3 pounds per cubic foot. The isocyanate orifice (not shown)is 1.3 mm in diameter, and the polyol orifice is 1.1 mm in diameter. Atthe end of two minutes, the interior door panel 7 is removed from themold 22 and is ready for a trimming operation.

While this invention has been described in terms of a preferredembodiment thereof, it will be appreciated that other forms couldreadily be adapted by one skilled in the art. Accordingly, the scope ofthis invention is to be considered limited only by the following claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A method ofmanufacturing a panel for a motor vehicle comprising:opening a moldcavity; placing a skinned insert with a foam backing into a mold cavitywith the insert foam backing facing an interior of the cavity;locationally fixing the insert within the mold cavity; covering theinsert with a flexible membrane placed into the mold cavity, theflexible membrane having a plurality of apertures; closing the moldcavity; injecting a polymeric backing material into the mold from a sideof the flexible membrane opposite the insert; flowing the polymericbacking material through the apertures of the flexible membrane;adhering the polymeric backing material to the insert foam backing;forming a rigid support for the insert and flexible membrane upon curingof the polyrmeric backing material within the mold; and opening the moldcavity.
 2. A method as described in claim 1 wherein locationally fixingthe insert within the mold is achieved by using a blade affixed withinthe mold.
 3. A method as described in claim 1 including placing a fibermat within the mold adjacent the flexible membrane on a side of theflexible membrane opposite the insert before injecting the polymericbacking material into the mold.
 4. A method as described in claim 1further including adhering the foam backing of the insert with a filmmembrane to prevent the injected polymeric backing material frompenetrating into the foam backing of the insert.
 5. A method ofmanufacturing a panel for a motor vehicle comprising:opening a moldcavity; placing a skinned insert with a foam backing into a mold cavitywith the insert foam backing facing an interior of the cavity;locationally fixing the insert within the mold cavity with a bladeaffixed within the cavity; covering the insert with a flexible vinylmembrane placed into the mold cavity, the flexible vinyl membrane havinga plurality of apertures; placing a fiber mat adjacent the flexiblevinyl membrane opposite the insert; closing the mold cavity; injecting apolymeric backing material into the mold from a side of the flexiblemembrane opposite the insert; flowing the polymeric backing materialthrough the apertures of the flexible membrane; adhering the polymericbacking material to the insert foam backing; forming a rigid support forthe insert and flexible membrane upon curing of the polymeric backingmaterial within the mold; and opening the mold cavity.